Buggy code:
class ChainsawCyclicBufferTableModel extends AbstractTableModel implements PropertyChangeListener , EventContainer { private static final int DEFAULT_CAPACITY = 5000 ; private static final String PANEL_CAPACITY = "CHAINSAW_CAPACITY" ; private boolean cyclic = true ; private int capacity = ChainsawCyclicBufferTableModel . DEFAULT_CAPACITY ; List unfilteredList ; List filteredList ; Set idSet = new HashSet ( capacity ) ; private boolean currentSortAscending ; private int currentSortColumn ; private EventListenerList eventListenerList = new EventListenerList ( ) ; private List columnNames = new ArrayList ( ChainsawColumns . getColumnsNames ( ) ) ; private boolean sortEnabled = false ; private boolean reachedCapacity = false ; private LoggerNameModel loggerNameModelDelegate = new LoggerNameModelSupport ( ) ; int uniqueRow ; private Set uniqueMDCKeys = new HashSet ( ) ; private Rule displayRule ; private PropertyChangeSupport propertySupport = new PropertyChangeSupport ( this ) ; public ChainsawCyclicBufferTableModel ( ) { } public void propertyChange ( PropertyChangeEvent evt ) { } public List getMatchingEvents ( Rule rule ) { } private void reFilter ( ) { } public int find ( Rule rule , int startLocation , boolean searchForward ) { } public void removeLoggerNameListener ( LoggerNameListener l ) { } public boolean addLoggerName ( String loggerName ) { } public void addLoggerNameListener ( LoggerNameListener l ) { } public Collection getLoggerNames ( ) { } public void addEventCountListener ( EventCountListener listener ) { } public boolean isSortable ( int col ) { } public void notifyCountListeners ( ) { } public void setDisplayRule ( Rule displayRule ) { } public void sort ( ) { } public boolean isSortEnabled ( ) { } public void sortColumn ( int col , boolean ascending ) { } public void clearModel ( ) { } public List getAllEvents ( ) { } public int getRowIndex ( LoggingEvent e ) { } public int getColumnCount ( ) { } public String getColumnName ( int column ) { } public LoggingEvent getRow ( int row ) { } public int getRowCount ( ) { } public Object getValueAt ( int rowIndex , int columnIndex ) { LoggingEvent event = null ; synchronized ( filteredList ) { if ( rowIndex < ( filteredList . size ( ) ) ) { event = ( ( LoggingEvent ) ( filteredList . get ( rowIndex ) ) ) ; } } if ( event == null ) { return null ; } LocationInfo info = null ; if ( event . locationInformationExists ( ) ) { info = event . getLocationInformation ( ) ; } if ( event == null ) { LogLog . error ( ( "Invalid<seq2seq4repair_space>rowindex=" + rowIndex ) ) ; throw new NullPointerException ( ( "Invalid<seq2seq4repair_space>rowIndex=" + rowIndex ) ) ; } switch ( columnIndex + 1 ) { case ChainsawColumns . INDEX_ID_COL_NAME : Object id = event . getProperty ( LOG4J_ID_KEY ) ; if ( id != null ) { return id ; } return new Integer ( rowIndex ) ; case ChainsawColumns . INDEX_LEVEL_COL_NAME : return event . getLevel ( ) ; case ChainsawColumns . INDEX_LOGGER_COL_NAME : return event . getLoggerName ( ) ; case ChainsawColumns . INDEX_TIMESTAMP_COL_NAME : <START_BUG> return new Date ( event . timeStamp ) ; <END_BUG> case ChainsawColumns . INDEX_MESSAGE_COL_NAME : return event . getRenderedMessage ( ) ; case ChainsawColumns . INDEX_MDC_COL_NAME : return getMDC ( event ) ; case ChainsawColumns . INDEX_NDC_COL_NAME : return event . getNDC ( ) ; case ChainsawColumns . INDEX_PROPERTIES_COL_NAME : return getProperties ( event ) ; case ChainsawColumns . INDEX_THREAD_COL_NAME : return event . getThreadName ( ) ; case ChainsawColumns . INDEX_THROWABLE_COL_NAME : return event . getThrowableStrRep ( ) ; case ChainsawColumns . INDEX_CLASS_COL_NAME : return ( info == null ) || ( ( info != null ) && ( info . getClassName ( ) . equals ( "?" ) ) ) ? "" : info . getClassName ( ) ; case ChainsawColumns . INDEX_FILE_COL_NAME : return ( info == null ) || ( ( info != null ) && ( info . getFileName ( ) . equals ( "?" ) ) ) ? "" : info . getFileName ( ) ; case ChainsawColumns . INDEX_LINE_COL_NAME : return ( info == null ) || ( ( info != null ) && ( info . getLineNumber ( ) . equals ( "?" ) ) ) ? "" : info . getLineNumber ( ) ; case ChainsawColumns . INDEX_METHOD_COL_NAME : return ( info == null ) || ( ( info != null ) && ( info . getMethodName ( ) . equals ( "?" ) ) ) ? "" : info . getMethodName ( ) ; default : if ( columnIndex <= ( columnNames . size ( ) ) ) { return event . getMDC ( columnNames . get ( columnIndex ) . toString ( ) ) ; } } return "" ; } private String getMDC ( LoggingEvent event ) { } private String getProperties ( LoggingEvent event ) { } public boolean isAddRow ( LoggingEvent e , boolean valueIsAdjusting ) { } public int getLastAdded ( ) { } public void fireTableEvent ( int begin , int end , int count ) { } private void fireNewKeyColumnAdded ( NewKeyEvent e ) { } public boolean isCyclic ( ) { } public int getMaxSize ( ) { } public void addNewKeyListener ( NewKeyListener l ) { } public void removeNewKeyListener ( NewKeyListener l ) { } public boolean isCellEditable ( int rowIndex , int columnIndex ) { } public void setCyclic ( final boolean cyclic ) { } public void addPropertyChangeListener ( PropertyChangeListener l ) { } public void addPropertyChangeListener ( String propertyName , PropertyChangeListener l ) { } public int size ( ) { } private class ModelChanger implements PropertyChangeListener { public void propertyChange ( PropertyChangeEvent arg0 ) { } } }

Fix:
return new Date ( event . getTimeStamp ( ) ) ;